1. Field of the Invention
The invention relates to a multistage process for the preparation of organopolysiloxanes by hydrolysis and condensation of chlorosilanes.
2. Description of the Related Art
Processes for the preparation of organopolysiloxanes are already known. In this context, reference may be made, for example, to DE 16 68 172 A, in which a water-soluble inert solvent is used. Furthermore, DE 854 708 B describes a process for the preparation of siloxane resins, in which alkoxylation, hydrolysis and condensation are carried out in one step, the reactions taking place in an uncontrolled manner.
The present invention relates to a process for the preparation of organopolysiloxanes, in which    in a first step, chlorosilanes are reacted with from 0.002 to 0.6 mol of water per mole of hydrolyzable chlorine and with from 0.3 to 1.6 mol of alcohol per mole of hydrolyzable chlorine, the molar ratio of water to alcohol being from 0.001 to 1.5,    in a second step, the reaction mixture obtained in the first step is optionally mixed with a water-insoluble organic solvent having a density of less than 0.9 kg/l, and water is metered in in amounts of from 0.2 to 100 mol of water per mole of Si component, and    in a third step, after the end of the reactions of the second step, the aqueous alcoholic phase is separated off.